U.S. patent number 6,923,938 [Application Number 10/271,867] was granted by the patent office on 2005-08-02 for hand-held pipettor.
This patent grant is currently assigned to Matrix Technologies Corporation. Invention is credited to Richard Cote, Robert Henry Zier.
United States Patent |
6,923,938 |
Cote , et al. |
August 2, 2005 |
**Please see images for:
( Certificate of Correction ) ** |
Hand-held pipettor
Abstract
A hand-held pipettor comprising a piston received in one end of
a cylinder, a pipettor tip removably secured to an opposite end of
said cylinder, means for reciprocating said piston through a
selected stroke to aspirate fluid into and to expel the thus
aspirated fluid from said pipettor tip, mutually spaced stop
members operatively associated with said manually driven means for
defining the range of said stroke and motor driven means for
varying the spacing between said stop members to thereby vary the
volume of fluid being aspirated into and expelled from said
pipettor tip.
Inventors: |
Cote; Richard (Sudbury, MA),
Zier; Robert Henry (Annapolis, MD) |
Assignee: |
Matrix Technologies Corporation
(Hudson, NH)
|
Family
ID: |
26986923 |
Appl.
No.: |
10/271,867 |
Filed: |
October 16, 2002 |
Current U.S.
Class: |
422/525;
704/E15.045; 73/863.32; 73/864; 73/864.01; 73/864.02; 73/864.11;
73/864.13; 73/864.14; 73/864.16; 73/864.18 |
Current CPC
Class: |
B01L
3/0224 (20130101); B01L 3/0227 (20130101); B01L
3/0279 (20130101); G10L 15/26 (20130101) |
Current International
Class: |
B01L
3/02 (20060101); G10L 15/00 (20060101); G10L
15/26 (20060101); B01L 003/02 () |
Field of
Search: |
;422/100
;73/863.32,864,864.01,864.02,864.11,864.13,864.14,864.16,864.18 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2071052 |
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Sep 1971 |
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FR |
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03186353 |
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Aug 1991 |
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JP |
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WO 91/05609 |
|
May 1991 |
|
WO |
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WO 01/57490 |
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Aug 2001 |
|
WO |
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WO 02/00345 |
|
Jan 2002 |
|
WO |
|
Other References
"A Fast and Low-Volume Pipettor with Integrated Sensors for High
Precision," 2000 IEEE, pp. 409-413. .
"The Automatic Pipette," American Diagnostica, May 2001. .
Handi-Pet Pipetting Gun, General Diagnostics, Mar. 1973. .
Eppendorf EDOS 5221, Instructions Manuel, Eppendorf, Germany, No
Date. .
Photocopy of transparency shown in presentation referred to in DX
above..
|
Primary Examiner: Warden; Jill
Assistant Examiner: Gordon; Brian R.
Attorney, Agent or Firm: Gauthier & Connors, LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority of provisional patent application
Ser. Nos. 60/329,704 and 60/329,706, each filed on Oct. 16, 2001.
Claims
We claim:
1. A hand-held pipettor comprising: a piston received in one end of
a cylinder; a pipettor tip removably secured to an opposite end of
said cylinder; manually driven means for reciprocating said piston
through a selected stroke to aspirate fluid into and to expel the
thus aspirated fluid from said pipettor tip; mutually spaced stop
members operatively associated with said manually driven means for
defining the range of said stroke; a voice recognition system that
decodes verbal commands and outputs the result to a central
processing unit, which in turn generates control signals; and motor
driven means for varying the spacing between said stop members to
thereby vary the volume of fluid being aspirated into and expelled
from said pipettor tip, said motor driven means including a drive
motor mechanically coupled to one of said stop members, said drive
motor being operative in response to electronic drive signals.
2. The hand-held pipettor of claim 1 further comprising an encoder
assembly associated with said drive motor and operative to generate
feedback signals to said central processing unit indicative of the
position of the said one stop member.
3. The hand-held pipettor of claim 1 further comprising a sleeve
surrounding and axially shiftable on said cylinder, said sleeve
being urged in one direction into a retracted position by the
pipettor tip removably secured to the said opposite end of said
cylinder, and being shiftable in the opposite direction to dislodge
said pipettor tip from said cylinder.
4. The hand-held pipettor of claim 3 further comprising spring
means for resiliently shifting said sleeve in the opposite
direction.
5. The hand-held pipettor of claim 4 further comprising lock means
for accommodating movement of said sleeve in the said one
direction, and for preventing movement of said sleeve in the said
opposite direction, and manually operable means for releasing said
lock means to accommodate the resilient shifting of said sleeve in
the said opposite direction.
6. The hand-held pipettor of claims 4 or 5 further comprising
pneumatic means for retarding the rate of movement of said sleeve
in the opposite direction.
7. A hand-held pipettor comprising: a piston received in one end of
a cylinder; a pipettor tip removably secured to an opposite end of
said cylinder; manually driven means for reciprocating said piston
through a selected stroke to aspirate fluid into and to expel the
thus aspirated fluid from said pipettor tip; mutually spaced
members operatively associated with said manually driven means for
defining a range of said stroke; motor driven means for varying the
spacing between said stop members to thereby vary the volume of
fluid being aspirated into and expelled from said pipettor tip; a
sleeve surrounding and axially shiftable on said cylinder, said
sleeve being urged in one direction into a retracted position by
the pipettor tip removable secured to the said opposite end of said
cylinder, and being shiftable in the opposite direction to dislodge
said pipettor tip from said cylinder; spring means for resiliently
shifting said sleeve in the opposite direction; lock means for
accommodating movement of said sleeve in the said one direction,
and for preventing movement of said sleeve in the said opposite
direction, and manually operable means for releasing said lock
means to accommodate the resilient shifting of said sleeve in the
said opposite direction; and pneumatic means for retarding the rate
of movement of said sleeve in the opposite direction.
8. The hand-held pipettor of claim 7 wherein said motor driven
means comprises a drive motor mechanically coupled to one of said
stop members, said drive motor being operative in response to
electronic drive signal.
9. The hand-held pipettor of claim 7 further comprising an encoder
assembly associated with said drive motor and operative to generate
feedback signals to said central processing unit indicative of the
position of the said one stop member.
10. A hand-held pipettor comprising: a piston received in one end
of a cylinder; a pipettor tip removably secured to an opposite end
of said cylinder; a manually driven plunger that is depressible to
reciprocate said piston through a selected stroke to thereby
aspirate fluid into and to expel the thus aspirated fluid from said
pipettor tip; mutually spaced stop members associated with said
manually driven plunger to define together with the piston a range
of the stroke; a voice recognition and processing system that
receives verbal commands and provides motor control signals; and a
motor that receives the motor control signals and includes a motor
shaft that may be rotated responsive to the motor control signals
to vary the range of the stroke defined by the mutually spaced
stops and the piston to thereby vary the volume of fluid being
aspirated into and expelled from said pipettor tip.
11. The hand-held pipettor of claim 10 wherein said motor shaft is
mechanically coupled to one of said stop members.
Description
FIELD OF THE INVENTION
The present invention relates generally to transfer and dispensing
devices for liquid reagents and samples, and more particularly to
hand-held pipettors.
BACKGROUND OF THE INVENTION
Pipetting systems are widely utilized in laboratories and hospitals
for withdrawing and dispensing relatively small, predetermined
quantities of liquids from one location to another, such as between
test tubes, microplates and other liquid receptacles. Portable, or
hand-held, pipettors are one type of pipetting system. Hand-held
pipettors generally include a housing, a cylinder including two
cylinder ends, with one end positioned within the housing and the
other end extending from the housing to form a pipettor tip holder,
a piston that moves within the cylinder to withdraw liquid from a
supply receptacle and dispense the liquid to a receiving
receptacle, and a plunger that drives the piston. While not a
permanent part of the pipettor, a disposable pipettor tip is
commonly attached to the end of the tip holder to retain the liquid
to be transferred. This tip can be removed from the tip holder,
disposed of, and replaced with a new tip. These hand-held pipettors
may be configured to transfer liquids by automated or manual
actuation of the pipettor. Automatically operated hand-held
pipettors generally include a motor for actuating the plunger to
move the piston within the pipettor cylinder for liquid transfer.
Manually operated hand-held pipettors require the pipettor user to
apply force to the plunger head, usually with a thumb or a finger,
to actuate the piston.
Hand-held pipettors may be designed as fixed volume pipettors,
where only one predetermined liquid volume is withdrawn and
dispensed, or as adjustable pipettors, where the user may set a
desired volume to be dispensed within a given volume range. Stop
features located within a pipettor determine the distance that a
piston will travel, also known as the stroke. The stroke
corresponds to the volume of liquid to be withdrawn and dispensed.
Hand-held pipettors commonly include two stops to establish the
limits of the stroke. For purposes of the foregoing description,
these two stops will be referred to as a front stop and a rear
stop. In this description, the front stop is the stop closest to
the tip holder and the rear stop is the stop closest to the plunger
head, or in a manual pipettor, the end of the plunger that is
manually actuated by a pipettor user. The stops in a fixed volume
pipettor are fixed, and the piston travels the same stroke during
each complete actuation of the plunger. In an adjustable volume
pipettor, at least one of the stops is movable to adjust the stroke
length of the piston, and thus the volume to be withdrawn and
dispensed.
In manual pipettor applications where the volume of liquid to be
transferred may vary frequently within a single application, the
pipettor user must frequently change the volume settings on the
pipettor, which can cause fatigue and potentially inaccurate volume
settings on the pipettor.
SUMMARY OF THE INVENTION
In one embodiment of the invention, a hand-held pipettor comprises
a housing including a front stop and a rear stop, a cylinder, a
piston that moves within the cylinder to draw and expel liquid, and
a plunger that moves the piston, the rear stop being movable by a
motor to adjust the volume of liquid to be aspirated and dispensed
by the pipettor.
In another embodiment of the invention, the pipettor includes a
voice recognition system that coacts with a central processing unit
to translate verbal commands for volume settings into electronic
signals that control the motor moving the rear stop.
In another embodiment, a hand-held pipettor for dispensing specific
liquid volumes comprises a cylinder having one end defining a tip
holder that accepts a disposable pipettor tip, a piston that moves
within the cylinder to withdraw and dispense liquid, and a manually
actuated plunger that moves the piston to at least one point of
resistance, the housing containing a tactile blow-out mechanism
that facilitates manual expelling of a remnant liquid in the
pipettor tip following the dispensing of specified liquid volumes.
The blow-out mechanism requires the pipettor user to apply a force
to the plunger through a first point of resistance to a second
point of resistance to expel remnant liquid from the pipettor
tip.
In a further embodiment, a hand-held pipettor for pipetting
applications comprises a cylinder having and end configured and
arranged to accept a disposable pipettor tip, a piston that moves
within the cylinder to withdraw and dispense liquid, a plunger that
moves the piston, and a manually actuatable tip ejector assembly
configured and arranged to dislodge the pipettor tip for disposal
following a pipetting application.
These and other features and advantages of the present invention
will now be described in greater detail with reference to the
accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view taken through a manual
hand-held pipettor in accordance with the present invention;
FIG. 2 is a horizontal sectional view on an enlarged scale taken
along line 2--2 of FIG. 1;
FIG. 3 is an enlarged view of a portion of FIG. 1; and
FIG. 4 is a schematic diagram of the voice recognition system.
DETAILED DESCRIPTION
A pipettor in accordance with the present invention is generally
indicated at 10 in FIG. 1. The pipettor includes a housing 12 with
an axially projecting cylinder 14. Cylinder 14 has a tapered distal
end defining a pipettor tip holder 16. A pipettor tip 18 is
removably secured by friction to the tip holder 16. The opposite
end of the cylinder has an enlarged head 20 with an internal ledge
22 on which is seated an O-ring 24 supporting an apertured seal 26.
A sleeve 28 has an apertured lower end 30 received in the cylinder
head 20. The sleeve 28 has an intermediate interior shoulder 32 and
an internally threaded open upper end 34. A front stop collar 36 is
biased upwardly against the internal shoulder 32 by a spring
38.
A piston 40 in the cylinder head 20 projects downwardly through the
seal 26. The piston is biased upwardly against the lower end of a
plunger 42 by a main spring 44. Plunger 42 extends upwardly through
the apertured lower end 30 of sleeve 28, and through the front stop
collar 36 and a tubular externally threaded screw 46, with its
upper end projecting from the top of the housing 12 and into an
axially depressable cap 48.
An enlarged intermediate section 58 of the plunger 42 defines upper
and lower shoulders 52 and 54. Shoulder 52 is biased against the
lower end of the screw 46 by the force of the main spring 44 acting
on the piston 40. The lower screw end thus serves as a rear
stop.
As can best be seen by additional reference to FIG. 2, the upper
end of the screw 46 is provided with external ribs 56 slidably
received in internal grooves 57 in a rotatable drive collar 60. An
external gear 62 on the drive collar 60 meshes with a drive pinion
64 on the output shaft of a motor 66.
Actuation of motor 66 will cause the drive collar 60 to rotate, and
the mechanical interengagement of the ribs 56 and grooves 57 will
result in a corresponding rotation being imparted to the screw 46.
The threaded engagement of the screw 46 with the upper end 34 of
the fixed sleeve 28 will result in the screw being shifted axially
to a desired setting of its lower end, which provides a rear stop
for the plunger 42 and the piston 40 biased agains its lower end by
the main spring 44.
The setting of the rear stop will limit the extent to which the
piston 40 can be retracted from the tubular portion of the cylinder
14, which in turn will control the volume of liquid that can be
drawn into the pipettor tip 18 during aspiration.
Aspirated liquid is dispensed from the pipettor tip by manually
depressing the cap 48 to advance the plunger 42 and the piston 40
against the biasing force of the main spring 44. The plunger will
continue to advance until the lower shoulder 54 of its enlarged
intermediate section 58 engages the front stop 36, creating a first
point of resistance which indicates that most of the aspirated
liquid has been dispensed. By manually applying additional force to
the plunger 42 in order to overcome the resistance of spring 38,
the piston will be advance further to insure that any residual
liquid will be "blown out" of the pipettor tip 18.
In another aspect of the invention, the pipettor includes a tip
ejector assembly generally indicated at 68 for removing a pipettor
tip 18 from the pipettor tip holder 16. As can best be seen by a
combined reference to FIGS. 1 and 3, the tip ejector assembly 68
includes a tip ejector actuator 70, a tip ejector shaft 72, a tip
ejector sleeve 73 movable with the tip ejector shaft, and a lock
collar 74. The lock collar allows one way movement of the tip
ejector shaft 72 and sleeve 73 in the direction of arrow A in FIG.
3, but does not allow movement of these components in the opposite
direction, the direction of arrow B, when the lock collar is
oriented in its locking position, as illustrated. Therefore, when a
disposable tip 18 is wedged upwardly onto the tip holder 16, the
tip ejector sleeve 73 is pushed upwardly in the direction of arrow
A. At the same time, the tip ejector shaft 72 will also move up a
distance equal to the distance traveled by the tip ejector sleeve
due to the fixed connection therebetween. The lock collar 74 will
allow movement of the tip ejector shaft 72 in the direction of
arrow A without resisting movement. However, the tip ejector shaft
72 will be prevented from moving in direction B toward the
disposable tip 18 by the locking action of the lock collar 74.
A spring 76 is positioned to bias the lock collar into an angled,
or locking position. The spring 76 keeps the tip ejector shaft 72
locked by the lock collar 74, and thus prevents the tip ejector
shaft and the ejector sleeve 73 from moving in the direction of
arrow B to dislodge and eject the pipettor tip 18.
Depressing the tip ejector actuator 70 in the direction of arrow C
will cause its tapered lower end 78 to coact with a mating inclined
surface of a ramp wedge 80, causing the ramp wedge to shift in the
direction of the lock collar, and creating a force lifting the lock
collar from its angled locked position to a raised unlocked
position. Once the lock collar is unlocked, the tip ejector shaft
is released to move through the lock collar in the direction of
arrow B under the force of spring 82. The tip ejector sleeve 73
will be correspondingly moved, causing the pipettor tip 18 to be
dislodged and ejected from the end of the pipettor tip holder
16.
In another embodiment of the invention, a damper mechanism includes
a piston 84 formed at the upper end of the tip ejector shaft 72.
The piston is encircled by an O-ring seal and enclosed in a chamber
86 vented to atmosphere by a one way check valve 88. Movement of
the tip ejector shaft in direction A causes air to be expelled from
the chamber 86 via the check valve, whereas movement in direction B
is retarded by the rate at which air can be readmitted to the
chamber via a smaller bleed hole 90. The retarded rate of travel in
direction B beneficially retards the velocity at which the pipettor
tip is ejected.
In another embodiment of the invention, as can be seen by reference
to FIGS. 2 and 4, the adjustment drive collar 60 is surrounded by
an encoder wheel 92 that rotates with the adjustment drive collar
and that comprises part of an encoder assembly 94. The pipettor
includes a voice recognition system VRS that translates verbal
commands 96 for volume settings and outputs the result 98 to a
central processing unit CPU. The CPU generates an electronic signal
99 that controls the motor 66, and may optionally receive input 100
from the encoder assembly 94 indicative of the position of the
adjustable stop. The pipettor's adjustment mechanism is thus moved
automatically to the position corresponding to the voice input
setting.
In light of the foregoing, it will be understood by those skilled
in the art that although the present invention has been described
with reference to a pipettor having a manually actuated piston,
certain aspects of the invention including the motor driven stop
adjustment mechanism, the voice recognition system, and the tip
ejection mechanism, are also applicable to pipettors having motor
driven pistons.
Modifications and improvements within the scope of the present
invention will become apparent to those skilled in the art. The
above description is intended to be purely illustrative, and does
not define the limits of the present invention.
* * * * *